<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
  var f = document.getElementById("f");
  var fw = f.contentWindow;
  fw.document.designMode = 'on';
  f.style.content = "'m'";
  fw.document.removeChild(fw.document.documentElement)
}

</script>
</head>
<body onload="boom();"><iframe id="f" src="data:text/html,"></iframe></body>
</html>
